Stefanie Sue Watson of Laurel in an undated photo. Watson went missing on her way to work in 1982. (Family photo)

Stefanie Sue Watson vanished on her way to work in the summer of 1982. Her car was found covered in blood, but she was not there. None of her remains were recovered except for a small piece of her skull.

The case went cold for decades until a DNA breakthrough in 2013 connected Watson’s killing to a man already in prison for an unrelated rape.

Now, nearly 34 years since Watson, 27, went missing, the case of her brutal slaying is closed. Prosecutors in Prince George’s County announced Monday that John Ernest Walsh pleaded guilty to second-degree murder and false imprisonment in Watson’s death.

“We hope that this will go a long way toward continued healing and closure for the victim’s family,” said John Erzen, a spokesman for the Prince George’s state’s attorney’s office.

Stefanie Sue Watson disappeared in Laurel on July 22, 1982. John Ernest Walsh was convicted of her murder 33 years later. DNA evidence solved the cold case, police say. (Aaron C. Davis/The Washington Post)

Walsh, 71, was sentenced to 33 years in prison after entering his plea in Watson’s death. He must serve the time on top of 72 years he received as a sentence in 1970 after he was convicted of first-degree rape and kidnapping.

Walsh had been in Maryland’s prison hospital for years before he was released on parole in 1980. He brutally beat and killed Watson before he was taken into custody again in 1989 for violating parole, police and prosecutors said.

Police think Walsh bludgeoned Watson while she was in the driver’s seat of her car in July 1982. Watson, a receptionist at a hospital in Laurel, did not make it to work or to a scheduled meet-up with a cousin, Chris Torres, in Pennsylvania the next day. Torres reported Watson missing.

Watson was planning to drop off her dog with Torres’s mother before she moved to Texas to be closer to her family.

“She was ready for a fresh start,” Torres said Monday. “What were the chances that she would disappear her last night in Laurel?”

Months later, witnesses saw a man dump a bag in the woods. Police recovered a skull fragment but nothing else, and the case went cold.

Then in 2013, police revisited Watson’s killing. Still in possession of the driver’s seat of her car, police arranged testing of a smear of blood on a section of the seat that a driver could not have reached.

The blood sample yielded a positive hit.

Police and prosecutors worked 15 months combing through databases to connect the DNA to Walsh and ensure their evidence was airtight before securing an indictment.

A lawyer representing Walsh could not be reached for comment.

Detective Bernie Nelson with the Prince George’s police cold-case unit said it is a relief to get some closure on an old case like Watson’s, which had a very high profile when it broke.

“A lot of people lose hope when cases get very old,” Nelson said. “We tell them to maintain hope and that something may break at any time.”

Torres said she is glad that police and prosecutors in Prince George’s did not give up on her cousin’s case. But the years in between, before any break in the case occurred, were torture, she said. That Walsh had preyed on Watson with decades left in his sentence adds to the disappointment, Torres said.

“You’re just in limbo and always wondering if it would ever happen,” Torres said. “It’s been a very long and horrible nightmare to live.”

In the nearly 34 years since Watson’s killing, her parents and brother have passed away. Her lone surviving immediate family member, sister Peg Adams, said Walsh’s guilty plea is bittersweet, bringing “all that sadness to the foreground again.”

And, Adams said, important questions remain: How did Watson cross Walsh’s path? Where is Watson’s body?

Adams said she hopes Walsh will lead detectives to the answers.

“I would like to be able to bury her,” Adams said. “We’ve never stopped missing her.”

Aaron C. Davis contributed to this report.